Is called for nouns that are specified and it can includes :
-Names of people , countries and cities like : محمد ، هند ، مكة ، مصر
-Pronouns like :
أنا ، أنت ، هو
-Nouns that are preceded by ( ال ) like :
المدرسه ، المنزل ، المعلم
- Demonstrative pronouns like :
هذا ، هذه ، هؤلاء
- connected words like :
التي ، الذي